Method of producing a reduced-calorie food product

ABSTRACT

Calories in a juice can be reduced by selectively removing more sucrose than primary sugars, for example, glucose and fructose. An acceptable flavor profile can be achieved since the primary sugars have a higher perceived sweetness than sucrose. The food product processing system for reducing calories can include multiple stages for filtering the juice to produce a clarified low-calorie juice having an acceptable flavor profile.

FIELD OF THE INVENTION

The present invention relates generally to food products, and moreparticularly to a method of producing reduced-calorie food products.

BACKGROUND OF THE INVENTION

High caloric intake has been associated with various concerns, such asweight gain, leading to health problems. As consumers become more healthand weight conscious, the calorie contents of foods are increasinglybecoming a significant consideration. Food manufacturers have marketedwellness foods with lower calorie contents to attract health and weightconscious consumers. A significant market now exists for low-caloriefoods.

However, low-calorie foods tend to lack flavor due to low sugar contentor low perceived sweetness. Manufacturers have tried to counter thisproblem by adding high amounts of unnatural sugar substitutes andflavorings to make the food taste more like natural products. Forexample, low-calorie orange juice is produced by diluting reduced sugarorange juice and adding large quantities of artificial sweeteners,coloring and flavorings to make it resemble natural orange juice.However, such artificial ingredients produce an off-taste or lingeringbitter aftertaste. Furthermore, certain artificial ingredients arebelieved to cause serious health problems and hence are notwell-received by consumers. This is particularly true with low-caloriebeverages.

From the foregoing discussion, it is desirable to provide a natural,reduced-calorie beverage without the negative characteristics ofconventional low-calorie beverages.

SUMMARY OF THE INVENTION

The present invention relates to reducing calories in food products. Thefood product can be a juice such as a fruit or a vegetable juice. In oneaspect of the invention, a method is disclosed which reduces calories byselectively removing more sucrose than primary sugars. Primary sugarsinclude, for example, glucose and fructose. An acceptable flavor profilewith a high perceived sweetness per calorie can be achieved since theprimary sugars have a higher perceived sweetness than sucrose.

In another aspect, a food processing system is disclosed for reducingcalories in juices. The food processing system comprises amicro-filtration stage for filtering a juice to produce a clarifiedjuice and a nano-filtration stage for selectively removing more sucrosethan primary sugars from the clarified juice to produce a clarifiedlow-calorie juice having an acceptable flavor profile.

These and other objects, along with advantages and features of thepresent invention herein disclosed, will become apparent throughreference to the following description and the accompanying drawings.Furthermore, it is to be understood that the features of the variousembodiments described herein are not mutually exclusive and can exist invarious combinations and permutations.

BRIEF DESCRIPTION OF DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention. In the followingdescription, various embodiments of the present invention are describedwith reference to the following drawings, in which:

FIG. 1 shows a process for forming a food product in accordance with oneembodiment of the invention; and

FIGS. 2-5 show filtration processes in accordance with variousembodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates generally to food products and beverageshaving reduced calorie content. Calorie reduction is achieved with no orless reliance on artificial sugars than conventional low caloriebeverages. In one embodiment, the low calorie beverage comprises ofnot-from-concentrate (NFC) or from-concentrate (FC) juices. Juice can beformed from fruit or vegetable sources. Preferably, the beveragecomprises citrus juices. More preferably, the beverage comprises anot-from-concentrate (NFC) juice. Other types of fruit or vegetablejuices include but are not limited to apricot, apple, grapefruit, lemon,tangerine, tangelo, kumquat, mango, pear, peach, pineapple, papaya,passion fruit, grape, strawberry, raspberry, currant, blueberry,blackberry, acai, lychee, kiwi, pomegranate, aronia, tomato, celery,onion, watercress, cucumber, carrot, parsley, beet, asparagus, potato,turnip, rutabaga, and any combination thereof.

FIG. 1 shows a process 100 for forming a reduced calorie beverage inaccordance with one embodiment of the invention. In one embodiment, theprocess forms an NFC orange juice. Forming other types of juices is alsouseful. The process includes providing a feed juice 105 for processing.The feed juice comprises a single strength juice derived by variousconventional techniques. Such techniques include, for example,mechanical extraction and finishing or reconstitution of juiceconcentrate with potable water.

Typically, the single strength juice has a brix of about 7° to about22°, and preferably from about 9° to 14°. In one embodiment, the singlestrength juice has a brix of at least 7°, preferably at least 9°. In yetanother embodiment, the single strength juice has a Brix of less than orequal to 22°, preferably less than or equal to 18°, more preferably lessthan or equal to 14°.

The use of a single strength juices with other brix levels are alsouseful. Lower or higher brix levels, for example, can be provided bymixing various fruit and/or vegetable juices, or by creating mixeddrinks, beverages or smoothie-type products. The feed juice can includevarious additional ingredients such as vitamins and minerals, asdesired. Other additives may also be useful. Ingredients can be addedearly or later in the process.

The feed juice is processed at step 110. Processing includes filteringthe feed juice to produce a permeate portion 160. In one embodiment, thepermeate comprises a low brix clarified juice. Clarified juice is ajuice in which the sinking solids have been separated from the feedjuice. Sinking solids, for example, include pulp, cloud components andother types of solids. The sinking solids form a primary retentateportion 135.

The permeate has a brix which is less than the brix of the feed juice.For example, in the case where the feed juice has a brix of about 12°,the permeate would then have a brix which is less than 12°. In oneembodiment, the brix of the permeate is about 0 to 30 percent less thanthe brix of the feed juice, preferably 0 to 20 percent less than thebrix of the feed juice. Providing a permeate having a brix which islower than the brix of the feed juice by other percentages may also beuseful, depending on the application. In one embodiment, the brix of thepermeate is about 5 to 8. Other brix values of the permeate less thanthe brix of the feed juice are also useful.

The sugar content in the feed juice comprises sucrose, glucose andfructose. Typically, the ratio of sucrose, glucose and fructose in thefeed juice is 2:1:1. or purposes of discussion, glucose and fructose arereferred to as primary sugars. As such, the ratio of sucrose and primarysugars in the feed juice is 1:1.

To reduce the amount of calorie content in the juice, carbohydrates areselectively separated. In one embodiment, sugars are selectivelyseparated. Preferably, sucrose is selectively removed while retainingprimary sugars in the permeate. The retentate forms a high brix solution155, having a brix which is greater than brix of the feed juice. In oneembodiment, the brix of the retentate is about 15° to about 25°, andpreferably about 20°. Providing other brix values for the retentatewhich is greater than brix of the feed juice is also be useful.

In accordance with one embodiment of the invention, sugar content of thepermeate comprises a sucrose to primary sugars ratio which is lower thanthe sucrose to primary sugars ratio of the feed juice. This is achievedby reducing the amount of sucrose in the sugar content of the permeate.In one embodiment, the sucrose content of the sugar contained in thepermeate is reduced to about 0-30 wt % while the primary sugars contentis about 70-100 wt %. The ratio of sucrose, glucose and fructose of thepermeate, in one embodiment, is about 2:1:1 to 1:2:2. The ratio ofsucrose and fructose of the permeate, in one embodiment, is about 1:40to about 4:1, and preferably between about 1:20 to about 2:1.

At step 170, the permeate is mixed with ingredients to form the finallow brix juice. One of the ingredients added is the primary retentate135 containing solids from the feed juice. PH adjusters, such asmonopotassium phosphate, potassium citrate, citric acid, malic acid, ora combination thereof can be added to adjust the pH of the juice. Otheringredients, such as vitamins, flavorings including orange oil (e.g.,PPOJ BN #95768) can also be added as desired. The total amount ofvitamins and flavoring can be about 0. wt % and 0.006 wt %,respectively. Other amounts are also useful. In one embodiment, avitamin premix comprising about B1, B6, C, magnesium, sucralose andacesulfame potassium. The premix, for example, includes about 0.2 wt %of B1, 0.1 wt % of B6, 46 wt % of C, 23 wt % of magnesium, 15.35 wt % ofsucralose and 15.35 wt % of acesulfame potassium. About 0.09 wt % of thevitamin premix is added to the clarified juice. Other formulationsincluding other ingredients are also useful.

Final processing of the juice is performed at step 180. The juice, forexample, is sterilized and packaged. The juice is packaged into, forexample, suitable cartons, jugs, cans or bottles. The packaged productsmay then be labeled and packaged for shipping.

In accordance with the invention, the low brix clarified juice isobtained using a multi-stage filtering process. The multi-stagefiltering process includes an initial stage for coarse filtering and asecondary stage for fine filtering. The coarse and fine filtering stagescan each include one or more sub-filtering stages. The sub-filteringstages can be in sequence, parallel or a combination thereof. In oneembodiment, the coarse and fine filtering stages are implemented withmembrane technology. Membrane technology includes microfiltration,nano-filtration and ultra-filtration. Other techniques, such ascentrifugation, are also useful.

The coarse filtering stage produces primary retentate and primarypermeate streams. The primary retentate contains the sinking solids ofthe feed juice while the primary permeate contains the clarified juice.The primary permeate is filtered by the fine filtering stage. The finefiltering stage selectively separates the carbohydrates or sugars fromthe clarified juice. Secondary retentate and secondary permeate streamsare produced by the fine filtering stage. The secondary retentatecontains a high brix solution while the secondary permeate contains thelow brix clarified juice.

In one embodiment, the permeate contains a higher ratio of fructose tosucrose than the retentate. This advantageously reduces the number ofcalories in the low brix clarified juice while maintaining an acceptableflavor profile of the juice. Preferably, the ratio is sufficient tomaintain an acceptable flavor profile. In one embodiment, flavorprofiles are found to be acceptable when the ratio of fructose tosucrose in the permeate is between about 1:4 and about 40:1, and morepreferably between about 1:2 to about 20:1.

Since sugars, such as fructose, are generally perceived to be sweeter byabout 10-70% than sucrose, a higher perceived sweetness per calorie canbe achieved by having a higher ratio of fructose to sucrose. Less or noartificial sweeteners need to be added to the final beverage blend toachieve an acceptable flavor profile, advantageously creating a more“natural” beverage product. Juices may also contain other sugars thatcan be selectively separated using the method of the instant invention.

Table 1 shows an example of the composition of a final orange juiceproduct having only about 50 calories per 8 oz. serving in contrast tothe conventional 110 calories per 8 oz. serving, in accordance with oneembodiment of the invention. This invention can be applied to deriveother higher or lower calorie products.

TABLE 1 Ingredient % weight g/serving (8 fl oz) Coarse filtrationRetentate 50 125 Fine filtration Permeate 50 125 Orange Oil 0.006 0.015Monopotassium 0.15 0.375 Phosphate Vitamin premix 0.09 0.225

FIGS. 2-5 show filtering processes in accordance with variousembodiments of the invention. Referring to FIG. 2, a multi-stagefiltering process 210 comprising a coarse filtering stage 220 and a finefiltering stage 250 is shown. In one embodiment, the coarse filteringstage 220 comprises a micro-filtration unit 221 which receives a feedjuice 205.

In one embodiment, the micro-filtration (MF) unit 221 comprises amicro-filter membrane to clarify the feed juice 205. However, any othermethod known to those skilled in the art, such as centrifugation orultra-filtration, can be used. The micro-filter membrane separates thefeed juice into a stream of sinking solids 235 (primary or MF retentate)and a stream of clarified juice 236 (primary or MF permeate). In oneembodiment, the MF unit produces an MF retentate of about 2× to 5×concentration. Preferably, the MF retentate is about 3× concentration.Other concentrations may also be useful. Higher concentrations, althoughmay be useful, have been found to extend processing time and/or requireadditional membrane units.

Various types of micro-filtration skids can be used to achieve thetarget concentration. In one embodiment, the MF unit comprises amicro-filtration skid from Koch Membrane Systems (USA). Other types ofmembranes are, such as those manufactured by Dow Chemical Company (US)and SCT Membralox (France), can be used, as well as other known systems.The pore size of the micro-filter membrane is preferably small enough toprevent larger undesirable molecules from passing through the membraneand affecting the efficiency of downstream filtration. In oneembodiment, the pore size is about 0.1 to 10 micrometers, whichcorresponds to a molecular weight cut-off (MWCO) of about 100,000 toabout 5,000,000.

The filtering is designed to have a predetermined output, e.g., gallonsper minute (gpm). The predetermined output is selected to satisfy thedesired throughput. For example, a production line for processing orangejuice has an output of about 100 gpm. Other predetermined output levelsare also useful. Pressure of the filtering process can be adjusted toachieve the predetermined output. Preferably, the feed stream is passedthrough the micro-filtration skid at a pressure sufficient to pass thedesirable aroma, flavor and nutrient components through micro-filtrationskid. One skilled in the art will know how to adjust the pressure, flowrate and other process conditions as required using the micro-filtrationskid of this present invention.

The MF permeate stream or clarified juice is processed by the finefiltering stage. The fine filtration unit comprises a nano-filtration(NF) unit which reduces sugar from the clarified juice to produce a lowbrix clarified juice (NF permeate) 260. The separated sugar forms a highbrix solution (NF retentate) 255.

In one embodiment, the NF unit selectively removes sucrose in theclarified juice. The selective removal of sucrose results in a sucroseconcentration of about 15 Brix to about 25 Brix. Preferably, the sucroseconcentration is about 20 Brix. The NF retentate, in one embodiment, isabout 2×-5× concentration of the clarified juice. Preferably, the NFretentate is about 2× concentration of the clarified juice. Higherconcentrations, although may be useful, have been found to extendprocessing time and/or require additional membrane units.

To selectively remove sucrose, NF membranes are employed. Various typesof NF membranes can be used in the NF unit. In one embodiment, thepore-size of the NF membrane is small enough to prevent more sucrosemolecules than primary sugar molecules from passing through. Sucrose hasa molecular weight (MW) of about 342 while the primary sugars such asfructose and glucose have a molecular weight of about 180. In oneembodiment, the pore size is about 0.001 microns, which corresponds to amolecular weight cut-off (MWCO) of about 200.

The pressure and flow rate are selected to cause a stream containing thesmaller primary sugar molecules to pass through the NF membrane andcollected in the NF permeate stream 260, while retaining the largersucrose molecules in the NF retentate stream 255. One skilled in the artwill know how to adjust the pressure as required using the NF membraneof this present invention.

The overall calorie reduction process can be carried out in varioustemperatures. Preferably, the overall process is performed atrefrigerated temperatures to produce a higher quality product.Refrigerated temperatures are preferably less than about 45° F., andmore preferably between about 32° to 38° F.

The system can be operated in batch mode or continuous close-coupledmode. When the system is operated in batch mode, interim stabilizationof the juice by heat pasteurization is useful to prevent enzyme andmicrobiological degradation. When the system is operated in continuousmode, intermediate pasteurization may be avoided.

The low brix clarified juice is then further processed, such as blendingwith MF retentate in the desired ratios. Other processes include thosedescribed in steps 178 and 180 of FIG. 1.

FIG. 3 shows another filtering process 310 in accordance with oneembodiment of the invention. The coarse or micro-filtration stage 320,as shown, is similar to that described in FIG. 2. For example, a feedjuice 305 is processed by a MF unit 321, producing a MF retentate stream335 containing sinking solids and MF permeate stream 336 containingclarified juice which is processed by the fine or nano-filtration stage350.

As shown, the NF filtration stage 350 comprises first and secondsub-stages 351 and 355. The first sub-stage comprises a first NF (NF1)filtration unit 352, similar to the NF filtration unit described in FIG.2. The MF permeate 336 is processed by the NF1 filtration unit 352,forming NF1 permeate 354 containing a low brix clarified juice and NF1retentate 353 containing a high brix solution. In one embodiment, thehigh brix solution comprises a sucrose concentration of about 15 Brix toabout 25 Brix, preferably about 20 Brix.

In one embodiment, the second sub-stage 355 comprises a reverse osmosis(RO) unit 356. Any suitable RO membrane system, such as the onesmanufactured by Koch Membrane Systems (USA) can be used, as well asother known systems. The RO filtration unit further concentrates the NF1retentate stream 353 to produce an RO permeate 360 containing very lowbrix water (e.g., about 1 Brix or less) and an RO retentate 362containing a very high brix solution (e.g., 40 Brix). The RO permeatewater stream can be recycled in the process for various purposes,including but not limited to blending or washing. For example, the watermay be blended with the reduced-calorie NF permeate stream 354 and theMF retentate stream 335 to form the final juice product.

The RO retentate (i.e. high sugar by-product) can be used as asupplementary sweetener in other juice products (not the low calorieproduct discussed in the present invention). Preferably, the proportionsof the respective components from the overall calorie reduction systemare chosen to sustain the mass balance between the various fractions andgenerate only a high sugar by-product that may be utilized as asupplementary sweetener. The high sugar by-product comprises, in oneembodiment, the NF retentate stream 255, such as shown in FIG. 2.

Alternatively, the NF retentate stream can be further concentrated by areverse osmosis unit to produce the high sugar by-product 362, as shownin FIG. 3. The high sugar by-product can be surged in a hold tank andre-used in other product types as needed. In the embodiment wherereverse osmosis is used, a smaller surge tank may be required, but anadditional water surge tank may be required for the water permeate. Bymaximizing use of lower calorie streams in producing the final juiceproduct, cost of raw materials, such as water and artificial sweeteners,is advantageously reduced, while at the same time, producing a productcloser to a “natural” reduced calorie product.

There can be additional NF units, preferably in parallel, but may alsobe in series, or a combination thereof. For example, FIG. 4 shows afiltering process 410 that includes a second sub-stage 355 thatcomprises a second NF (NF2) filtration unit 456. The NF1 permeate stream354 is processed by the NF2 unit to form NF2 permeate 464 containing alow brix clarified juice and NF2 retentate 462 containing a high brixsolution. In one embodiment, the low brix solution comprises a sucroseconcentration of about 5 Brix. Alternative configurations are alsouseful. The number of units used is determined by efficiency and costconsiderations.

FIG. 5 shows a filtering process 510 in accordance with anotherembodiment of the invention. The filtering process further includes avolatile recovery unit 520 coupled to the NF1 permeate stream. Thevolatiles recovery unit can improve the flavor of the final beverageproduct by preserving aroma and flavor volatile compounds that caneasily be lost due to volatilization during processing. Such aroma andflavor volatile compounds include, for example, low molecular weightalcohols or oils, such as ethanol and methanol, as well as aldehydes andesters.

In one embodiment, the volatiles recovery unit heats the NF1 permeatestream and strips it with a stripping agent to remove aroma or flavorvolatiles. The stripping agent can be steam or an inert gas, such asnitrogen or carbon dioxide. Heating can be carried out using heatexchangers or live steam injection to a stripping temperature above theequilibrium temperature. The stripped volatiles 530 may then,optionally, be condensed and recombined with the NF2 permeate 464 andthe RO permeate 360 to form the final juice product.

While the invention has been particularly shown and described withreference to various embodiments, it will be recognized by those skilledin the art that modifications and changes may be made to the presentinvention without departing from the spirit and scope thereof. The scopeof the invention should therefore be determined not with reference tothe above description but with reference to the appended claims alongwith their full scope of equivalents.

1. A method for processing a food product comprising: providing a juice;and processing the juice to selectively remove more sucrose than primarysugars to produce a stream of clarified low-calorie juice whilemaintaining an acceptable flavor profile, the primary sugars having ahigher perceived sweetness than sucrose.
 2. The method of claim 1wherein the juice comprises a fruit or vegetable juice.
 3. The method ofclaim 2 wherein the juice comprises not-from-concentrate orange juice.4. The method of claim 2 wherein the juice comprises from-concentrateorange juice.
 5. The method of claim 1 wherein the juice comprises asingle strength juice having a brix of about 7° to about 22°.
 6. Themethod of claim 5 wherein the clarified low-calorie juice comprises abrix of less than the brix of the single strength juice.
 7. The methodof claim 6 wherein the brix of the clarified low-calorie juice is about0 to 30% less than the brix of the single strength juice.
 8. The methodof claim 6 wherein the brix of the clarified low-calorie juice is about10 to 20% less than the brix of the single strength juice.
 9. The methodof claim 6 wherein the clarified low-calorie juice comprises a brix ofabout 5 to
 8. 10. The method of claim 1 wherein the primary sugarscomprise fructose.
 11. The method of claim 10 wherein the clarifiedlow-calorie juice comprises a ratio of sucrose to fructose of betweenabout 1:40 to about 4:1.
 12. The method of claim 11 wherein theclarified low-calorie juice comprises a ratio of sucrose to fructose ofbetween about 1:20 to about 2:1.
 13. The method of claim 1 wherein thestep of processing the juice comprises: coarse filtering the juice toproduce a primary retentate stream and a primary permeate stream, theprimary retentate stream comprises sinking solids of the juice and theprimary permeate stream comprises a clarified juice; and fine filteringthe primary permeate stream to selectively remove more sucrose thanprimary sugars, the fine filtering produces a secondary retentate streamand a secondary permeate stream, the secondary retentate streamcomprises a high brix solution and the secondary permeate streamcomprises the clarified low-calorie juice.
 14. The method of claim 13wherein the clarified low-calorie juice comprises a ratio of sucrose tofructose of between about 1:40 to about 4:1.
 15. The method of claim 14wherein the clarified low-calorie juice comprises a ratio of sucrose tofructose of between about 1:20 to about 2:1.
 16. The method of claim 13wherein the coarse filtering step comprises microfiltering.
 17. Themethod of claim 16 wherein the microfiltering comprises passing thejuice through a micro-filtration membrane having a molecular cut-off ofabout 100,000 to about 5,000,000.
 18. The method of claim 16 wherein thefine filtering step comprises nano-filtering.
 19. The method of claim 18wherein the nano-filtering comprises passing the primary permeate streamthrough a nano-filtration membrane having a molecular cut-off of about200.
 20. The method of claim 13 wherein the fine filtering stepcomprises nano-filtering.
 21. The method of claim 20 wherein thenano-filtering comprises passing the primary permeate stream through anano-filtration membrane having a molecular cut-off of about
 200. 22. Afood product processing system comprising: a micro-filtration stage forfiltering a juice to produce a primary retentate stream and a primarypermeate stream, the primary retentate stream comprises sinking solidsof the juice and the primary permeate stream comprises a clarifiedjuice; and a nano-filtration stage for selectively removing more sucrosethan primary sugars from the clarified juice, the primary sugars havinga higher perceived sweetness than sucrose, and the nano-filtration stageproduces a secondary retentate stream and a secondary permeate stream,the secondary retentate stream comprises a high brix solution and thesecondary permeate stream comprises a clarified low-calorie juice havingan acceptable flavor profile.
 23. The food product processing system ofclaim 22 wherein the clarified low-calorie juice comprises a ratio ofsucrose to fructose of between about 1:40 to about 4:1.
 24. The foodproduct processing system of claim 23 wherein the clarified low-caloriejuice comprises a ratio of sucrose to fructose of between about 1:20 toabout 2:1.
 25. The food product processing system of claim 22 whereinthe micro-filtration stage comprises a micro-filtration membrane havinga molecular cut-off of about 100,000 to about 5,000,000.
 26. The foodproduct processing system of claim 22 wherein the nano-filtration stagecomprises a nano-filtration membrane having a molecular cut-off of about200.
 27. The food product processing system of claim 22 wherein thenano-filtration stage comprises a first nano-filtration sub-stage and asecond nano-filtration sub-stage, the first nano-filtration sub-stageprocesses the primary permeate stream to produce a first nano-filtrationretentate stream and a first nano-filtration permeate stream, the secondnano-filtration sub-stage processes the first nano-filtration retentatestream to produce a second nano-filtration retentate stream and a secondnano-filtration permeate stream.
 28. The food product processing systemof claim 27 wherein the first nano-filtration sub-stage comprises anano-filtration unit.
 29. The food product processing system of claim 28wherein the second nano-filtration sub-stage comprises a reverse osmosisunit.
 30. The food product processing system of claim 29 wherein secondnano-filtration permeate stream comprises a low brix water by-productthat is recycled in the processing system.
 31. The food productprocessing system of claim 30 wherein the low brix water by-productcomprises a brix of less than or equal to about 1°.
 32. The food productprocessing system of claim 29 wherein the second nano-filtrationretentate stream comprises a high sugar by-product that is used as asupplementary sweetener.
 33. The food product processing system of claim32 wherein the high sugar by-product comprises a brix of about 40°. 34.The food product processing system of claim 27 further comprises avolatiles recovery unit for stripping volatiles from the firstnano-filtration permeate stream.
 35. The food product processing systemof claim 34 wherein the stripped volatiles are recombined with thesecond nano-filtration permeate stream to form the clarified low-caloriejuice.